Buttonhole-sewing machine



J KJEWICZ. BUTTONHOLE SEWING MACHINE. APPLICATION men MAR. 11. 1921.

1,402,073. Patented Jdn. 3, 1922.

2 SHEETS-SHEET I- v ATTys.

J. KlEWICZ.

BUTTONHOLE SEWING'MACHINE.

APPLICATION man MAR. 11.1921.

Patented Jan. 3,

lnvenfor. John Ki Bwi c IJYM Mk III/I/I/II/7/7 ENETEQ STATES PATENT QFFECE.

JOHN KIEWICZ, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REEOE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

BUTTONHOLE-SEWING MACHINE.

Application filed March 11, 1921.

To all whom it may concern:

Be it known that I, J OHN Kmwroz, a c1t1- zen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Buttonhole-Sewing Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to buttonhole sewing machines, and particularly to the workclamping device by which the work is held clamped while the stitching is being done on the buttonhole.

In order to stitch a buttonhole satisfactorily on a buttonhole sewing machine it is necessary that the work should-be stretched slightly 01' held taut in a direction transversely of the buttonhole, and the object of e present invention is to provide a novel .eans for thus stretching the work slightly hen it is clamped in position by the work ramps.

The work-holding means usually used in buttonhole sewing machines comprises a clamp plate on which the work is laid and two work clamps constructed to clamp the work against the clamp plate, the two work clamps being situated on either side of the buttonhole. In my present invention I pro pose to make the clamp plate with two grooves situated on opposite sides of the sewing opening through the clamp plate and also situated at a slightly greater distance apart than the work clamps when they are in their elevated position, and I propose to construct the work clamps so that when they are depressed to clamp the work they will enter the grooves and during thisoperation will be separated slightly thereby stretching the work. 7

My invention is capable. of use in connection with buttonhole sewing machines of different types but I have herein chosen to illustrate it as it might be embodied in a sewing machine of the type illustrated in United States Patents No. 749,776, J an. 19, 1904, and No. 1,088,652, Feb. 24,1911. I desire to state, however, that the invention is not limited to its use in connection with buttonhole sewing machines such as illustrated Specification of Letters Patent.

Patented J an. 3, 1922.

Serial No. 4514539.

in connection with other buttonhole sewing machines. 1

In the drawings, Fig. 1 is a side view of a buttonhole sewing machine of the type illustrated in the above-mentioned patents having my improvements applied thereto.

Fig. 2 is a plan view of the clamp plate and work clamps removed.

Fig. 3 is a bottom plan view of the clamp plate.

Fig. i is an enlarged section on substantially the line 4-4, Fig. 1 showing the work clamped.

Fig. 5 is a view similar to Fig. 1 showing the clamps raised.

The sewing machine herein illustrated comprises the bed frame 1 from which rises the overhanging arm 2 that supports the vertically reciprocating needle bar 3 carrying the needle 4:. 5 indicates the buttonhole cutter which is carried by a lever 6 pivoted to turn about a rock shaft 7 carried by the frame. The work-holding means comprises the usual clamp plate 8 on which the work to is placed, and which is provided with the slot or sewing opening 9 through which the needle operates, and the two work clamps l0 situated on opposite sides of the sewing.

opening and carried by arms 11 that are piv otally mounted to the clamp plate at 12.

In the sewing machine herein illustrated the arms 11 are carried by a rocker 13 which is pivoted to the rock shaft 12 and the rocker has a tail let extending rearwardly there from, said tail underlying a lever 15 pivoted to the frame at 16. This lever 15 i provided with a handle 17 so that by swinging the handle 17 to the left of Fig. 1 the lever 15 may be pressed against the tail 14: thereby to elevate the work clamps 10. The work clamps are also raised automatically at the end of the stitching operation on the buttonhole by a mechanism similar to that described in the above-mentioned patents and which comprises a latch member 18 which is pivoted to the lever 15 and is adapted to be engaged by an arm 19 forming part of the controlling mechanism which controls the starting and stopping of the machine. When the buttonhole is completed and the stop mechanism comes into play to stop the machine the arm 19 at the same time engages the latch lever 18 and draws downwardly I thereon thereby causing the lever to dc J pressthe taill laand elevatethe'work clamps c pivoted at 21 and carrying the" depending all as shown inthe above-mentioned patents, The work olampsiare released at'the beginning of the sewing operation'by the lever V 'latch lever 18" is released from the arm 19.

The parts thus far described are, or may i be, all as shown in the above-mentioned pats cuts and therefore a more detail description isnotnecessary; r

' In'my present invention the two'arms 11 carrying the work clamps ,10 are pivotally' mounted on the rocker 13 as' shown at-23-so that the arms may swing about the pivots 23 toward and from each other; The springs which automatically depress the work clamps into work-clamping position are shown at 24: and they are in the nature of through which the pins 25 loosely extend and which is carried by a bracket 27 secured to'the clamp plate 8. i

The clamp plate 8 1s provicled with two grooves 28 situated on opposite sides of the sewing opening 9 and extending parallel the buttonhole thereto, each groove preferably having inclined sidewalls so as to present a V formation. 'The under face of each work clamp 10 has a similar V-shape to fit the groove 28, each under face comprising the two inclined surfaces 29 and 30.

The work clamps are constructed so that when they are in their raised position,

shown in Figs. 1 and 5, they will be slightly nearer together than the'grooves 28 and as" a result when the clamps are depressed to clamp the work the inner inclined faces 30 of the work clamps will first engage the inner walls of the grooves as shown in dotted lines'Fig. 5, so that in entering the grooves and assuming the work-clamping position shown in Fig. 4: the work clamps are spread or separated slightly. This spreading of the work clamps by their entering the grooves 28 operates to stretch the workand place it under the desired tension so that can be properly stitched it becomes necessary to stitch a buttonhole 7' therein. 7 r r When the work w is placed on the clamp plate with the work clamps raised it will have the position shown in Fig. 5 and when the work clamps are depressed theinclined faces 30 thereof will engage the work at substantially the points'31 and when the work Vmachine the buttonhole cutter operates to coil springs encircling rods or pins 25 that" rise from the arms 11. Theupper ends of the springs abut against a bridge piece 26' the faces 30 thereof with'the work '31: will tend to stretch the work so that the portion thereofwhich spans the sewing opening '9 'will be under tension. The stretching of the work, therefore, is accomplished partly by forcing'the work into the grooves "28 and partly by the spreading movement of the work clamps as they enter the grooves.

Means are aiso provided whereby when the work clamps are raised at the end of each sewing operation they will be auto- 'matically moved toward each other back raisedQ The action of these "cam surfaces against the arms 11 will force the arms in- 'wardly into the position shown in Fig, 5.

'It' sometimes happens that during the stitching of a buttonhole the thread will 7 skip thus making it necessary to sew theLbuttonhole' over-again. In this type of sewing cut the buttonhole only afterthe buttonhole is sewed; If, however, it is necessary to sew the buttonholeoveragain, then such second sewing operation is performed on a cutbuttonhole and' when the work clamps are depressed'and are carried into the grooves the action of the work clamps on the fabric having a cut buttonhole therein is likely to stretch or'open the buttonhole to such an extent that the stitches wouldnot be properly formed.

* I have provided therefore means by which the work clamps are prevented from being spread when the "sewing machine is operating on a'cut buttonhole. Such means comprises a locking lever 34 pivoted. to one ofthe clamp arms ll'at and lnving a notch 36 adaptedto engage a pin 37 carried 11 are freetobe spread but if the lever 34 is swung into' dotted line positionfFig'Z when the work clamps "are raised thereby causing the pin 37 to enter the notch 36', then thearms 11 will be held from spreading movement so that when the work clamp is depressed said armsnwill'remain in the dotted line position Fig. 5 and will therefore exert no spreading or stretching action on the work to. This lever 34 can be' readily operated manually by the operator whenever for a second time. L V

I claim. a r V 1. In a buttonhole sewing machine, the combination with a clamp plate having a on each side'of said opening, of work-clamp ing' arms, a rocking block to which the arms are pivoted so that the arms may swing tosewing opening and provided with a groove f ward each other, the rocking movement of the block permitting the arms to move toward and from the clamp plate, each arm carrying at its end a work-clamping portion shaped to fit the groove, the work-clamping portions of said arms normally being situated a less distance apart than the grooves, whereby when the work-clamping arms are moved into work-clamping position they engage the sides of the grooves and are spread thereby to stretch the cloth.

2. In a buttonhole sewing machine, the combination with a clamp plate having a sewing opening and two V-shaped grooves on opposite sides of said opening, of two work clamps pivotally mounted on said clamp plate for movement toward and from the latter and also mounted for movement toward and from each other, said work clamps having clamping faces to -fit the grooves and being normally situated at a less distance apart than the grooves, whereby when the work clamps are depressed into clamping position they engage the inner walls of the grooves and are separated thereby stretching the work.

3. In a buttonhole sewing machine, the combination with a clamp plate having a sewing opening and two V shaped grooves on opposite sides of said opening, of two Work clamps mounted on said clamp plate for movement toward and from the latter and toward and from each other, said work clamps having clamping faces to fit the grooves and being normally situated at a less distance apart than the grooves, whereby when the work clamps are depressed into clamping position they have a spreading action as they enter the grooves thereby to stretch the work, and means to move said clamps positively toward each other when they are raised.

4. In a buttonhole sewing machine, the combination with a work plate, of two workclamping arms pivotally mounted thereon 5. In a buttonhole sewing machine, the combination with a clamp plate having a sewing opening and a groove on each side of the sewlng opening, sald grooves having inclined walls, of two work clamps pivotally mounted on the clamp plate and having inclined clamping faces, and means to move the work clamps toward the clamp plate, the inclined faces of the work clamp and groove cooperating during such movement to spread the clamps thereby stretching the work.

6. In a buttonhole sewing machine, the combination with a clamp plate having a sewing opening and a groove on each side of the sewing opening, said grooves having inclined walls, of two work clamps pivotally mounted on the clamp plate and having inclined clamping faces, means to move the work clamps toward and from the clamp plate, the engagement of the inclined faces of the work clamps and grooves operating to spread the clamps during the work clamping movement thereby to stretch the work, and means to move the clamps together during their movement away from the clamp plate.

'7. In a buttonhole sewing machine, the combination with a clamp plate, of two work clamps pivotally mounted thereon and capable of movement toward and from each other, means to cause a separating movement of the work clamps as they'move into work clamping position, and means to lock the work clamps from separating movement.

In testimony whereof, I have signed my name to this specification.

JOHN KIEWICZ.

Certificate of Correction.

It is hereby certified that in Letters Patent N 0. 1

case in the Patent Oflice.

[SEAL] KARL FENNIDNGQ Acting Commissione ofPatentsq 

